<xsl:stylesheet version="1.1"
                xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                xmlns="http://www.w3.org/2000/svg"
                xmlns:xlink="http://www.w3.org/1999/xlink"
                xmlns:random="http://exslt.org/random"
                xmlns:math="http://exslt.org/math"
                xmlns:exsl="http://exslt.org/common"
                xmlns:temp="http://temp.org/temp"
                extension-element-prefixes="exsl"
                exclude-result-prefixes="random math exsl">

	<xsl:param name="bird-width">15</xsl:param>            
	<xsl:param name="bird-height">15</xsl:param>            
	 
  	<xsl:template match="thing[@id='bird']" mode="render">
  		<xsl:param name="base-x"/>
  		<xsl:param name="base-y"/>
	 	<xsl:param name="state">default</xsl:param>
		<rect x="{$base-x - $bird-width div 2}" y="{$base-y - $bird-height}" width="{$bird-width}" height="{$bird-height}" fill="blue" stroke="black"/>
  	</xsl:template>
 
 	
</xsl:stylesheet>